000 AXNT20 KNHC 301735 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT MAY 30 2009 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1615 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 53W S OF 11N MOVING W 10-15 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOWS A WELL-DEFINED MAXIMUM IN MOISTURE EAST OF THE WAVE AXIS. THE WAVE HAS LITTLE SURFACE SIGNATURE AT THIS TIME...BUT IS ANALYZED IN THE GFS 700 AND 850 MB WINDS AS A DISTINCT TROUGH AND VORT MAX. SCATTERED MODERATE CONVECTION IS S OF 6N BETWEEN 38W-50W. A NEW TROPICAL WAVE IS ANALYZED TO BE ALONG 21W MOVING ABOUT 15 KT. LITTLE TO NO DEEP CONVECTION IS CURRENTLY ASSOCIATED WITH IT AND ONLY A MODEST MAXIMUM IN THE TOTAL PRECIPITABLE WATER IMAGERY CAN BE OBSERVED JUST EAST OF THE WAVE AXIS. RAWINSONDE OBSERVATIONS FROM DAKAR AND BAMAKO INDICATE THAT THE SHALLOW WAVE EXITED THE WEST COAST OF AFRICA YESTERDAY. THE GFS ANALYSES DO NOT DEPICT THE WAVE CLEARLY...THOUGH THE ECMWF APPEARS TO HAVE A BETTER HANDLE ON THE LOCATION AND AMPLITUDE OF THE WEAK WAVE. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 3N25W CROSSING THE EQUATOR NEAR 36W AND INTO NE BRAZIL NEAR 1S45W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS S OF 6N E OF 5W. SCATTERED MODERATE CONVECTION IS S OF 3N BETWEEN 38W-50W. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT IS PRESENT ACROSS THE GULF AND AT 30/1500 UTC EXTENDED FROM THE FLORIDA PENINSULA JUST SOUTH OF TAMPA WEST-SOUTHWESTWARD TO 23N 90W AND THEN WESTWARD TO 23N 96W. THE NUMEROUS BUOYS AND AN 1158 UTC QUIKSCAT PASS ALLOWED FOR RELATIVELY EASY IDENTIFICATION OF THIS SOMEWHAT STRONG COLD FRONT FOR THIS TIME OF YEAR. AHEAD OF THE FRONT EAST OF 88W SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS OBSERVED AS INDICATED BY INFRARED AND VISIBLE SATELLITE IMAGERY...LIGHTNING DATA...AND COASTAL RADARS. ADDITIONALLY...ISOLATED MODERATE CONVECTION HAS ALSO DEVELOPED NEAR THE WESTERN END OF THE FRONT. SURFACE WINDS AWAY FROM THE DEEP CONVECTION ARE LESS THAN 20 KT. IN THE UPPER LEVELS...WINDS ARE UNIFORMLY WESTERLY UP TO A MAXIMA OF 70 KT. CARIBBEAN SEA... DEEP CONVECTION OVER THE CARIBBEAN IS UNDER QUITE SUPPRESSED TODAY AS A SAHARAN AIR LAYER COVERS MOST OF THE SEA...AS SHOWN BY THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS ARE OCCURRING IN THE SOUTHWESTERN CARIBBEAN...PERHAPS BEING FORCED BY A MID-LEVEL TROUGH ANALYZED BY THE GFS. SURFACE WINDS ACROSS THE CARIBBEAN MAX ONLY AROUND 20 KT AS THE PRESSURE GRADIENT IS NOT PRONOUNCED WITH THE BERMUDA HIGH SOMEWHAT WEAK AND DISPLACED NORTHEASTWARD. IN THE UPPER LEVELS...SUBSIDENT TROUGHING DOMINATES WITH A CLOSED LOW PRESENT JUST NORTH OF PUERTO RICO. ATLANTIC OCEAN... A 1026 MB SURFACE HIGH IS LOCATED NEAR 31N49W. JUST EAST OF THIS HIGH...A WEAKENING STATIONARY FRONT EXTENDS FROM 31N27W TO 25N37W TO 26N44W. ISOLATED SHOWERS ARE LOCATED WITHIN 30 NM OF THE FRONTAL BOUNDARY. A SURFACE TROUGH IS LOCATED BETWEEN 25N57W SOUTHWARD TO 19N57W. THIS FEATURE HAS BEEN RELATIVELY STATIONARY DURING THE LAST DAY AND IS PRODUCING ISOLATED SHOWERS WITHIN 120 NM OF THE TROUGH AXIS. BY FAR THE MOST CONVECTIVELY REGION IS IN ASSOCIATION WITH THE COLD FRONT OVER THE FLORIDA PENINSULA AND A TROUGH EAST OF THE FRONT. THE TROUGH EXTENDS FROM 31N76W TO 27N78W AND SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS OCCURRING WITHIN 300 NM EAST OF THE TROUGH AXIS. THE FRONT AND TROUGH ARE SUPPORTED BY A RATHER VIGOROUS SHORT-WAVE TROUGH OVER THE SOUTHEASTERN US. SURFACE WINDS AWAY FROM THE DEEP CONVECTION ARE GENERALLY LIGHT ACROSS THE ATLANTIC WITH WINDS ONLY UP TO 20 KT. $$ LANDSEA